Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109
Milos Tichy , Jana Ticha, and Michal Kocer
Klet Observatory, Zatkovo nabrezi 4, CZ-370 01 Ceske Budejovice, Czech Republic
We examine the observations of the dust tail evolution, nucleus duplicity, and rapid fading of comet C/2004 S1 (Van Ness), which disappeared in late October 2004, within a month of its discovery. We show that the comet's behavior is consistent with an erosion model, developed for the SOHO comets of the Kreutz sungrazer system, except that the erosion energy required for comet Van Ness to understand its light curve is extremely low, on the order of 10,000 cal/mole. Thus, nucleus erosion was energetically easier than water ice sublimation. The comet's complete disintegration was preceded, several days before discovery, by nucleus splitting accompanied by a brief, copious release of sizable refractory debris.